Police used several water cannon trucks to disperse protesters, spraying jets of blue dye into the crowds and sending hundreds fleeing. Police have used the dye to identify protesters.

It was the heaviest use of water cannons by police and many people hit with the water developed coughs, suggesting an irritant may have been mixed with the water.

As riot police advanced protesters fell back to their next barricade, unlike past rallies when they stood and clashed with police, throwing petrol bombs and bricks.

Protestors have thrown petrol bombs at police as violence flared during a banned march in Hong Kong.

Protestors have thrown petrol bombs at police as violence flared during a banned march in Hong Kong.

Along the march route, protesters torched and trashed metro stations and hundreds of shops, throwing goods onto the streets. Several Chinese banks were targeted.

Protesters have in the past targeted Chinese banks and shops with links to mainland China, leaving mainland Chinese living in Hong Kong worried about their safety.

The unrest was sparked four months ago by a bill that would have allowed extradition to mainland China for trial in Communist Party-controlled courts. It has since widened into a pro-democracy movement.